A power nap is a short sleep which terminates before the occurrence of deep sleep or slow-wave sleep (SWS), intended to quickly revitalize the subject. The expression was coined by Cornell University social psychologist James Maas.
Characteristics
The power nap is thought to maximize the benefits of sleep versus time. It is used to supplement normal sleep, especially when a sleeper has accumulated a sleep deficit.
Various durations are recommended for power naps, which are very short compared to regular sleep. The short duration of a power nap is designed to prevent nappers from sleepin...

Last year I once got really drunk at a party. When I got home I sent an email to work saying I wasn't going to make it due to too much alcohol and requested a day off. My boss didn't seem to make a problem off it.

@CatPlusPlus: I'm searching for some references, but here the idea is to minimize the service time of serving memory chunks allocated using calloc. Obviously, memory allocated using malloc() should not using a "clean" page if dirty and unallocated pages exists, but there may not be any if your system is pretty unloaded